Human Immunodeficiency Virus (HIV) infection, and the resulting Acquired Immunodeficiency Syndrome (AIDS) remain threats to global public health, despite extensive efforts to develop anti-HIV therapeutic agents. Some HIV-infected individuals eventually develop broadly neutralizing antibodies (bNAbs), which neutralize a large panel of HIV viruses. These individuals show delayed development of AIDS, even in the absence of any treatment for HIV infection.
One previously characterized HIV-1 neutralizing mAb, called b12, can bind to a site on gp120 that is required for viral attachment to its primary cellular receptor, CD4. mAb b12 was derived from a phage display library, a process which makes it impossible to know if the antibody was naturally present in an infected person, or was the result of a laboratory combination of antibody heavy and light chains. b12 can neutralize about 75% of Glade B strains of HIV-1 (those most common in North America), but it neutralizes less than 50% of other strains of HIV-1 found worldwide. Therefore, there is a need to develop additional neutralizing antibodies for HIV-1.